The long weekend comes to a close with the Trolls in the Forest tour that sees bizarre Norwegian folk act Trollfest returning to London for a UK exclusive with fellow trolls Finsterforst in tow. The Underworld's alternative entrance is employed, foreshadowing a woefully thin turnout for such a rare concert.

Nonetheless, Finsterforst commence their set assuredly with a total of seven mud-smeared band members crammed on to the Underworld's miniscule stage. Interweaving folk and black metal together, these Germans regale the audience with musical adorations regarding their homeland, namely the beautiful Black Forest. Material from 2012's output 'Rastlos'very closely echoes the sophisticated Finnish folk metal ofMoonsorrow while earlier efforts encapsulate a more fun and 'party' face of folk metal. Viking-esque clean vocals and black metal rasps stud the music with film score-epic keyboards and a jaunty Korpiklaani styled accordion supporting melodic guitar leads.With songs regularly clocking in over the eight minute mark, Finsterforst do a fantastic job at retaining the audience's keen attention. While the Underworld is anything but jam-packed, headbanging and hearty applauses accompany each song.

The comic nature of intro tape 'Trolltramp' from Trollfest's new album 'KaptainKhaos' perfectly sets the mood for the forthcoming proceedings. Launching into the cartoon-y title track of this album, these Norwegians instantly barrel roll the audience with their thoroughly entertaining and down-right weird take on folk metal. A hyperactive concoction of Finntroll, orthodox Balkan folk and Latinomusic with lyrics growled in the non-existent bastardized offspring of Norwegian and German (endearingly named Trollspråk) ensures that Trollfest are immersing themselves into avant-garde metal. They constantly change pace, textures and instruments, relentlessly leaving the listener guessing. In spite of the bipolar nature of their music, the band makes this work sublimely, rejuvenating metal by exploring ground that has never been walked on. Violin, saxophone, banjo and accordion are just some of the instruments that make their presence known in these nutty Norwegians' sound.

New songs including 'Ave Maria', 'Vulkan' and 'Die Grosse Echsen' storm through the venue successfully while older favourites including 'Der Jegermeister', 'Karve' and 'Brumbelbassen' work superbly in the live environment. A mosh pit even erupts and the audience overall is significantly more lively than the standard placated London metal crowd. Donned in white lab coats, the seven members of Trollfest (eight when joined by their session violin player Sareeta of Asmegin fame) keep a dynamic energy that mirrors the music for the entire duration of the show. Interaction between the headliners and the fans is met with positive reactions with the audience singing along when asked and reacting overwhelmingly positively to Trollfest's banter. With two small drum kits (adorned with customised rubber ducks) alongside the standard one, the stage truly is over-subscribed with bouncing metalheads and this energy is channelled into the audience.Given the chaotic nature of the music, the only real issue with the sound is that the accordion is occasionally buried under the aural assault

'RundtBålet' sees these trolls vacate the stage only to return for their encore, each member dressed in a different outfit with a range including an alligator onesie, Jesus, a caveman and some kind of Roman soldier. 'Den ÅpnaSjø', 'Renkespill' and 'HelvetesHunden GARM' satisfy the crowd's strong craving for more but when the headliners vacate the stage, they return again with Finsterforst for a solid rendition of 'Essenfest' and one final alcoholic-tinged 'hurrah' that makes the bank holiday even sweeter.

It is rare for a metal show to be anywhere near as colourful as Trollfest's. Their folk/avantgarde metal approach undisputedly snatches the crown of party metal with has no intention of giving it back. Here's hoping that Trollfest will return to the UK and bring a much needed stimulant to whacky and crazily amusing concerts.